878 U.S. NATIONAL MUSEUM BULLETIN 23 7 part 2 



May vesper sparrow nests are more apt to be parasitized than later 

 nests. H. W. Hann (1937), M. M. Nice (1937a), J. Van Tyne (in 

 Bent, 1953), and others have described the cowbird's habit of watching 

 host species in the process of building nests. A. J. Berger (1951a) 

 states: "I believe that there is a correlation between parasitism and 

 proximity to higher vegetation. In general, parasitized nests in fields 

 were near bordering woodlots or thickets, whereas non-parasitized 

 nests were not near such vegetation. Thickets and trees apparently 

 provide perches and cover for female cowbirds on the alert for nest 

 building activity." 



Banding. — John L. George (MS.), writing of his study of the 

 vesper sparrow in southern Michigan, reports that "of eight adults 

 banded in 1948, six (75 percent) returned * * * the following year; 

 and of 16 banded adults present in 1949, 5 (31 percent) returned in 

 1950." One pair remained mated for two years, but none of 45 banded 

 nestlings was seen in subsequent breeding seasons. L. H. WaUdnshaw 

 (MS.) studied a male vesper sparrow that returned to the same 

 nesting territory for 4 consecutive years; for the first 2 years this 

 male had the same banded mate. 



Distribution 



Range. — Northern Minnesota, central Ontario, southern Quebec 

 and Nova Scotia south to northern TamauHpas and the Gulf coast. 



Breeding range. — The eastern vesper sparrow breeds from northern 

 Minnesota (eastern Marshall County), central and northeastern On- 

 tario (Rossport, Moose Factory, Lowbush), southern Quebec (Blue 

 Sea Lake), Prince Edward Island, and northern Nova Scotia south to 

 central Missouri (Appleton City, St. Louis), southern Illinois (Mur- 

 physboro. Mount Carmel), central Kentucky (Lexington), northeast- 

 ern Tennessee (Tate Spring, Johnson City), western and central 

 North Carolina (Weaverville, Greensboro), and south central Virginia 

 (western Amelia County, Richmond). 



Winter range. — Winters from central Texas (Ingram, Waco), Ar- 

 kansas (Rogers), southern Illinois (Murphysboro), central southern 

 Kentucky (Mammoth Cave), West Virginia (French Creek), south- 

 eastern Pennsylvania (Edge Hill), central New Jersey (Princeton), 

 and Connecticut (Guilford) south to northeastern Tamaulipas (Mata- 

 moros) , the Gulf coast, and central Florida (Seven Oaks, Micco) ; 

 occasionally north to Ontario (Point Pelee, Toronto) and Nova Scotia 

 (Wolfville); in migration west to eastern Nebraska, eastern Kansas, 

 and easteiTi Oklahoma. 



Casual records. — Casual in Yucatdu (Chichen Itzd) , southern Florida 

 (Key West), and Bermuda. 



